The invention relates to a shielded, highly radioactive, wet chemical cell of an atomic plant, in particular a large cell of reprocessing plants for irradiated atomic fuel. These types of cells are hereinafter called hot cells.
The invention relates in particular to a method for recognizing (detecting) drop leaks in drip leakage-endangered sections of system parts of hot cells, wherein the drip leakage-endangered sections, at least in the region of the possible path of a leakage drop, are irradiated with light and the radiation reflected from the irradiated region is evaluated for drip leakage recognition.
The invention also relates to a hot cell with a contrivance for recognition of drip leakage in drip leakage-endangered sections of the hot cell. Here, the contrivance displays a source of light capable of being directed toward the region of the possible path of a leakage drop and an arrangement for evaluation of the radiation reflected from the irradiated region for the purpose of drip leakage recognition.
The initially mentioned hot cell, as well as the method and the contrivance for drip leakage recognition, are known from the German Offenlegungsschrift* No. 31 38 484 of the applicant. In the known hot cells of this species and/or in the case of the known method of this species, drip leakages are traced by arranging remote controlled television cameras on computer controlled manipulators, by traveling over the leakage point-endangered region of the hot cell by the television camera under computer control, and the pictures displayed by the television camera are examined for leakage points. FNT *Offenlegungsschrift=laid open print, published patent application (specification) examined only as to obvious defects but not as to patentability.
This teaching that is known from German Patent No. 31 38 484 Al has a series of advantages. It enables automatic checking of the leakage point-endangered regions, for example the frequently 3000 to 4000 flange connections in a hot cell. It moreover enables a search for leaks without personnel having to enter the hot cells for this purpose. In this manner, preliminary decontamination work becomes superfluous, having as its consequence a considerable saving of time in the search for leakage. To locate larger leaks, the known contrivance is the best suited. However, small drip leakages when making a visual evaluation of the pictures displayed by the television camera are frequently overlooked.